Document-based productivity applications, such as word processors, presentation software, spreadsheet applications, web browsers, and the like typically display document content in an authoring pane. This authoring pane is often centered within the application, consuming a majority of the application's display space. However, document-based applications may also provide functionality in ancillary panes, which may be displayed adjacent to the main document content. Spellcheckers, style selectors, search boxes, and the like, may be presented in ancillary panes, enabling user interaction with the feature without occluding main document content.
Some ancillary panes display content derived from the main document pane. However, extracting and processing content for display in an ancillary pane may be computationally expensive, particularly for large documents, and when the underlying content is being added to, updated, and deleted frequently as a user edits the document, efficiently maintaining the content of the task pane has proved challenging.
In addition, some productivity applications don't display add-in output renderings efficiently. For example, a word processor may include add-ins for a spell checker. Providing displays of information in these add-ins, which can be in an ancillary pane, can be difficult since the content in the authoring pane may be incompatible with the content stored by the add-in and displayed in the ancillary pane.